Table 1 Cardiorenal syndrome classification

Type 1 (acute cardio-renal syndrome)

Abrupt deterioration of cardiac function that results in acute kidney injury (AKI)

Type 2 (chronic cardio-renal syndrome)

Chronic abnormalities of cardiac function leading to progressive chronic kidney disease (CKD)

Type 3 (acute reno-cardiac syndrome)

Abrupt and primary worsening of kidney function that initiates acute cardiac dysfunction

Type 4 (chronic reno-cardiac syndrome)

CKD that promotes reduction of cardiac function

Type 5 (secondary CRS)

Systemic disorders that impair both cardiac and renal function